Improvement in sewing-machines



L. W. LANGDON Sewing Machine Shuttle.

Patented Jan, 22, 1861.

' UNITED STATES PATENT .OFFICE.

L. W. LANGDON, OF NORTHAMPTON, MASS, ASSIGNOR TO HIMSELF, AND HIRAMWELLS AND D. G. LITTLEFIELD, OF SAME PLACE.

IMPROVEMENT IN SEWING-MACHINES.

Specification forming part of Letters Patent No. 31,211, dated January22, 1861.

To all whom it may concern:

Be it known that I, L. W. LANGDON, of Northampton, in the county ofHampshire and State of Massachusetts, have invented certain Improvementsin Shuttles for Sewing Machines and Looms, of which the following is afull, clear, and exact description, reference being had to theaccompanying drawings, making part of this specification, in which-Figure 1 is a view of the shuttle; Figs. 9,3, sections upon the line B Bof Fig. 1, enlarged; Fig. 4, detail to be referred to hereinafter.

It is very desirable that the thread, as it passes from the shuttle, besubjected to a uniform and equable tension; and the attainment of thisend is the objectof my present invention, which consists in applying thepressure of a spring directly to the thread upon the bobbin inconnection with a device whereby this pressure is relieved by the draftof the thread whenever it becomes excessive or beyond the limit assignedto it.

To enable others skilled in the art to understand my invention, Iwillproceed to describe the manner in which'I have carried it out.

In the said drawings the thread is wound upon a bobbin, A, which isadapted to the shuttle in any ordinary or well-known manner. To theinterior of the shuttle is pivoted, at the points 6, a friction-plate,i, which is drawn down upon the barrel of the bobbin, or upon the threadwound thereon, by a spring, g. This spring is secured at one end totheshuttle by the screw b, and at the other it is hinged to a short arm,00, attached rigidly to the frictionplate, the arm at making such anangle with the friction-plate that when the parts are in the positionrepresented in Fig. 2 the spring shall draw the plate down upon thebobbin and produce friction thereon, and when the friction-plate isthrown into the position seen in Fig. 3 the arm a: shall pass the centerand hold it in the position seen in this figure.

The tension of the spring g may be adjusted so as to produce more orless friction upon the bobbin by the screw b, and torelieve thisfriction, should it at any time become excessive, the thread from thebobbin is passed through the hole n in the presser-plate down beneaththe lip Sand out of the holefin the shuttle, and should the pressure onthe bobbin at any time exceed the amount to which the springg isadjusted the thread 0 will raise the plate 1' sufficiently to relievethe bobbin of the extra pressure and allow the thread to render.

In shuttles, as ordinarily constructed and operated, it is evident thatas the thread passes from the bobbin out of the shuttle it will. drawperpendicularly from that point of the bobbin only which is opposite tothe hole in the shuttle, and that from all other points of the bobbin itwill draw obliquely, and this produces great unevenness in the tensionupon the shuttle-thread. To remedy this I pass the thread over a curvedguide, from which it passes to the hole in the shuttle, and by thismeans is drawn perpendicularly from all parts of the bobbin, Fig. 1.

In the shuttle represented in the accompanying drawings the curved guide0 is made in one piece with the pressenplatei; but itis obvious thatthey may be made independent the one of the other without altering thespirit of my invention. It will be observed that immediately over thescrew b, by which the tension of the spriugg is adjusted, the shuttle isperforated with a hole, It, through which a screwdriver may be insertedfor the purpose of turning the screw andadjusting the tension of thespring, the shuttle being so placed in the race that the hole It shallbe uppermost, as seen in Figs. 1, 2, and 3. By this means the tensionupon the shuttle-thread may be adjusted without removing the shuttlefrom its race or breaking the thread for the purpose.

What lclaim asmyinveution, and desire to secure by Letters Patent, is-

Producing tension upon the shuttle-thread L. W. LANGDON.

Witnesses:

SAM. OooPER, P. E. TESOHEMAOHER.

